Carbon footprint is not as small as you think

Author

Director, Cambridge Centre for Climate Change Mitigation Research (4CMR), University of Cambridge

Disclosure statement

Douglas Crawford-Brown, and the Cambridge Centre for Climate Change Mitigation Research, receives funding from the EPSRC and European Commission. He is affiliated with the Tyndall Centre for Climate Change.

The UK government has made much of claims that its climate policies have been successful in reducing carbon emissions. This claim is based on the data used to create the national inventories required under the United Nations Framework Convention on Climate Change, which wealthier nations such as the UK publicise as proof of their commitment to decarbonising their economies.

However, the authors of a recent paper published in Environmental Research Letters have calculated the carbon footprint differently. They reveal that the government’s claims are rose-tinted, to say the least. They calculate what we might view as the “real” carbon footprint of the UK: measured in terms of consumption, rather than production.

The official national inventories hide an uncomfortable feature of the global economy - that of “carbon leakage.” In the production-based accounting that these inventories use, carbon is assigned to a nation according to where it is emitted. This feature has been bemoaned justifiably by nations such as China that have become the “factory of the world,” producing goods for export to consuming nations such as the UK. The result is a continuing growth in carbon emissions from China, the products of which are in significant measure flowing around the globe to consumers.

Were a global carbon tax imposed on carbon released in production, the burden would fall squarely on the shoulders of the developing economies in which goods are increasingly produced. This seems anything but equitable, seeing as much of the products of these emissions are globally consumed.

An alternative is consumption-based accounting, in which the ultimate consumer of a product is held accountable for the emissions that took place during production, regardless of where that production occurs.

The paper by Minx et al is one of a growing stream of publications aimed at addressing and making possible this shift to consumption-based accounting. Performing such accounting is anything but straightforward, and results are much higher in uncertainty than production-based accounting. Still, the methods and analyses are needed, both as a way of bringing equity to our global climate policies, and as a strategy for identifying the root causes of carbon emissions in patterns of personal consumption.

The message of their paper is clear: when one uses consumption-based accounting, a very different picture emerges - of both the national average emissions, and where those emissions are or should be assigned. Under consumption-based accounting, the UK has not been declining in emissions, simply shifting those emissions to countries such as China. The same is true for the EU generally.

This method reveals that wealthy urban areas do not have lower per capita emissions than poorer areas: they are simply net importers of carbon from other (manufacturing) parts of the UK. This reveals that wealthier people have consumption levels of carbon that the traditional method of measuring carbon footprint hides from view.

The analysis is not without its problems. The idea of following carbon through a chain from extraction, to manufacturing, to sale, and on to consumption is still in its infancy. Due to the difficulty of this, results of different studies vary by factors of two, three and sometimes more. And reducing consumption of any given good, such as a refrigerator in the UK, may not reduce global carbon emissions. It may simply drive down the price of goods globally, allowing poorer nations to hoover up those goods.

But we will not be able to test policies based on shifting consumption patterns until we can assess their impact. Studies such as this one set the stage for a future in which those who consume will be just as responsible for carbon as those who produce. It may not be a message welcomed by the UK government, but it will be a step forward in truthfully tackling the risks of climate change.